K-strategy species plays a pivotal role in the natural attenuation of petroleum hydrocarbon pollution in aquifers

• Published in: Journal of hazardous materials 2021-10, Vol.420, p.126559, Article 126559
• Main Authors: Ma, Yan, Zhao, Hangzheng, Shan, Qianjuan, Xu, Yanqiu, Yu, Minda, Cui, Jun, Liu, Tong, Qiao, Longkai, He, Xiaosong
• Format: Article
• Language: English
• Subjects: Co-occurrence network; Ecological strategy; Evaluation standard; Quantitative real-time PCR
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2021.126559

The natural attenuation of petroleum hydrocarbons is inseparable from the action of microorganisms, while the degradation methods and ecological strategies of microorganisms in petroleum-contaminated aquifers are still under debate. In the present study, 16 S rRNA sequencing and quantitative real-time polymerase chain reaction were used to assess the potential microbial degradation of petroleum hydrocarbons, and the ecological strategy of microorganisms under petroleum stress was analyzed through a co-occurrence network. The results showed that the microbial community in sediments exhibit higher efficiency and stability and stronger ecological function than that in groundwater. Keystone species coordinated with the community to execute ecosystem processes and tended to choose a K-strategy to survive, with the aquifer sediment being the main site of petroleum hydrocarbon degradation. Under natural conditions, the presence of petroleum hydrocarbons at concentrations higher than 126 μg kg-1 and 5557 μg kg-1 was not conducive to the microbial degradation of polycyclic aromatic hydrocarbons and alkanes, respectively. These results can be used as a reference for an enhanced bioremediation of contaminated groundwater. Overall, these findings provide support to managers for developing environmental management strategies. [Display omitted] •K-strategy species in petroleum-polluted aquifers maintain a community structure.•Communities are more efficient and stable in aquifer sediments than in groundwater.•Communities have better ecological function in sediments than in groundwater.•The degradation of alkane and PAHs by microorganisms differs among aquifers.•These findings provide support to managers for developing environmental management strategies.